NATURAL PHILOSOPHY, 



THE REPULSIVE FORCE AND THE RESISTING MEDIUM. 



M. Faye's examination of Plana's Memoir on this profound sub- 

 ject appears in a recent number of Comptes Rendus of the French 

 Academy (No. 7). The discussion relates to the very basis of nat- 

 ural philosophy, involving the explanation of the highest astronomical 

 and meteorological phenomena. The celestial world does not obey 

 one force alone attraction, but a duality of forces attraction and 

 repulsion. The first depends on the mass alone, the second on the 

 surface and the heat. The former is propagated instantaneously and 

 through all matter, the latter successively, being easily intercepted by 

 a medium. But both forces are universal. They are founcl wher- 

 ever there is heat and mass in the systems of the most distant stars, 

 and in all the bodies which we can touch ; in all phenomena which 

 arise in experimental philosophy and the arts. 



ELECTRICITY OF THE ATMOSPHERE. 



The origin of the electricity of the atmosphere has long occupied 

 the attention of physicists, and at different times they have apparently 

 settled down on some plausible hypothesis, which merely offered a 

 probable explanation of the phenomena, without leading to new facts 

 or pointing out new lines of research. 



The earth, as is now well known, is almost a perfect conductor for 

 the most feeble currents of electricity, provided the contact with it 

 of the electrified body be sufficiently broad. The aerial covering 

 which surrounds it, however, is a non-conductor, which is capable 

 of confining electricity in a condition of accumulation or of diminu- 

 tion, and of preventing the restoration of the equilibrium which, 

 without the existence of this insulator, would otherwise take place. 



The hypothesis was at first advanced that the earth attracted the 

 ethereal medium of celestial space and condensed it in a hollow strat- 

 um around the whole globe ; that the electricity of the atmosphere 

 was due to the action of this exterior envelope. Dr. Hare, our coun- 

 tryman, has presented this hypothesis with considerable distinctness. 

 Without denying the possibility or even probability of such a distri- 



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